Health risk assessment on human exposed to environmental polycyclic aromatic hydrocarbons pollution sources.

To assess how the human exposure to environmental carcinogenic polycyclic aromatic hydrocarbons (PAHs) pollution sources generated from industrial, traffic and rural settings, we present a probabilistic risk model, appraised with reported empirical data. A probabilistic risk assessment framework is integrated with the potency equivalence factors (PEFs), age group-specific occupancy probability and the incremental lifetime cancer risk (ILCR) approaches to quantitatively estimate the exposure risk for three age groups of adults, children, and infants. The benzo[a]pyrene equivalents based PAH concentrations in rural, traffic, and industrial areas associated with age group-specific occupancy probability at different environmental settings are used to calculate daily exposure level through inhalation and dermal contact pathways. Risk analysis indicates that the inhalation-ILCR and dermal contact-ILCR values for adults follow a lognormal distribution with geometric mean 1.04x10(-4) and 3.85x10(-5) and geometric standard deviation 2.10 and 2.75, respectively, indicating high potential cancer risk; whereas for the infants the risk values are less than 10(-6), indicating no significant cancer risk. Sensitivity analysis indicates that the input variables of cancer slope factor and daily inhalation exposure level have the greater impact than that of body weight on the inhalation-ILCR; whereas for the dermal-ILCR, particle-bound PAH-to-skin adherence factor and daily dermal exposure level have the significant influence than that of body weight.